1. Field of the Invention
The present invention relates to a laser processing apparatus, and more specifically to a laser processing apparatus which can control the number of laser beams.
2. Description of the Related Art
As a method for manufacturing a shadow mask for deposition of an organic material of an organic light emitting diode (OLED) display, a wet etching method has been used. However, when the wet etching method is used for manufacturing the shadow mask, the shadow mask may not have exquisite patterns due to non-uniformity from the wet etching, and the shadow mask cannot have a wide deposition angle because a side shape of the pattern is formed in a given shape. In addition, when a large-scale shadow mask is manufactured, the thickness of a steel plate is increased due to a limit in rolling technology, and the patterns become non-uniform because the wet etching time is increased.
To solve such problems in the wet etching, a method for manufacturing a shadow using a laser processing apparatus has been devised to manufacture a large-scale shadow mask having exquisite patterns and a standard side angle. However, when a single laser beam is used for manufacturing the shadow mask using the laser processing apparatus, manufacturing time is increased, and when the single laser beam is divided into a plurality of laser beams by a diffractive optical element (DOE), the number of laser beams is fixed so that the size of the shadow mask may not vary. In order to manufacture various sizes of shadow masks, the number of laser beams may be controlled by changing the diffractive optical element, but in this case, the diffractive optical element should be changed each time in order to split the laser beam into various numbers of laser beams so that shadow mask processing time is increased and manufacturing cost is also increased.
The above information disclosed in this Background section is only for enhancement of an understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.